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51.
Agnieszka Tomza-Marciniak Bogumi?a Pilarczyk Ma?gorzata B?kowska Marek Ligocki Marcelina Gaik 《Biological trace element research》2012,149(3):345-351
This study was designed to evaluate the degree of exposure of pet dogs from an urban area of NW Poland to selected metals, including toxic Cd and Pb. The study was conducted on a group of 48 healthy dogs. The serum concentration of the analysed elements followed the order Fe > Al > Zn > Cu > Mn > As > Sr > Pb > Cd > Cr > Ni > V. The presence of cadmium and lead was found in all the serum samples tested. The average contents of these elements were 0.309 and 0.489???g/mL. The factors that played the greatest role in the intake of the analysed elements were diet and breed-dependent size of dogs. Small-sized dogs had higher concentrations of all elements compared with large dogs, with statistically significant differences noted for Cu, Pb, Cd and Sr. It was also found that dogs receiving commercial and mixed food had more metals in serum compared with dogs on homemade food (except strontium). The present study showed elevated concentrations of some heavy metals (Pb, Cd, Fe and Cu) in serum of pet dogs, which is probably due to the excess elemental load of this area. Given that no information is available on the concentrations of strontium, vanadium and aluminium in dogs, further research is necessary to determine certain reference values which would allow for an easier interpretation of results and evaluation of exposure to these elements. 相似文献
52.
Profiling of gene expression in bacteria is now being used to uncover unknown genes expressed in particular genetic backgrounds or environmental conditions. Obtaining the best possible information from the expected avalanche of such experiments will require standardization of both experimental approach and statistical analysis. The first such experiments reveal challenges, pitfalls and reasonable solutions. 相似文献
53.
Anna Filipek Agnieszka Zasada Urszula Wojda Robert Makuch Renata Dbrowska 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》1996,113(4):745-752
Using a procedure developed to purify calcyclin from mouse Ehrlich ascites tumor cells calcyclin was purified from smooth muscle of chicken gizzard. Chicken gizzard calcyclin bound to phenyl-Sepharose in a calcium dependent manner as did mouse EAT cells and rabbit lung calcyclin but appeared to be more acidic than its mammalian counterparts as revealed by ion exchange chromatography on Mono Q. Chicken gizzard calcyclin bound 45Ca2+ on nitrocellulose filters and exhibited a shift in electrophoretic mobility on urea-PAGE depending on Ca2+ concentration. Crosslinking experiments with BS3 showed that chicken gizzard calcyclin was able to form noncovalent dimers. As indicated by a decrease in maximum tryptophan fluorescence emission of caldesmon (about 14% at 1:1 molar ratio) and displacement of calmodulin from its complex with caldesmon, chicken gizzard calcyclin binds caldesmon. This binding was, however, much weaker than that of calmodulin and could not influence the interaction of caldesmon with actin. In consequence, calcyclin was unable to reverse the inhibitory effect of caldesmon on actin-activated Mg2+-ATPase activity of myosin in the presence of Ca2+. 相似文献
54.
Eleven strains of Escherichia coli were isolated from 54 bank voles living in the LomZa Landscape Park of the Narew River Valley, indicating that E. coli is not common in the alimentary tract of these mammals. On the basis of pulsed-field gel electrophoresis and computer-assisted analysis, the isolates were grouped into six genotypes at similarities of 39%. Chromosome length of E. coli under study differed by as much as 900 kb, ranging 2.7-3.6 Mb. All strains were susceptible to amikacin and ciprofloxacin, whereas, for tetracycline, streptomycin, ampicillin, and cefonicid, different results were noted. No differences were detected among the plasmid complements of eight strains (73%), for which plasmid profiles revealed the presence of two plasmidic bands. One, three and four plasmids were observed in a plasmid pattern of single isolates. The observation from the study indicated the high genetic polymorphism among the isolates recovered from the animals of one species living in the same environment. 相似文献
55.
Subspecific relationships of the European beaverCastor fiber have been obscured by failure to follow the rules of the International Code of Zoological Nomenclature and remain an open
issue. Inconsequence in the use of subspecies names caused a nomenclatural as well as a taxonomic confusion. We discuss these
controversial and incorrect nomenclatural decisions, and recognize 9 nominal subspecies of European beaver, bearing 9 available
names:C. f. fiber Linnaeus, 1758,C. f. galliae Geoffroy, 1803, C. f. albicus Matschie, 1907,C. f. vistulanus Matschie, 1907,C. f. pohlei Serebrennikov, 1929,C. f. birulai Serebrennikov, 1929,C. f. tuvinicus Lavrov, 1969,C. f. belorussicus Lavrov, 1981, andC. f. orientoeuropaeus Lavrov, 1981. 相似文献
56.
Agnieszka Fiuk Piotr T. Bednarek Jan J. Rybczyński 《Plant Molecular Biology Reporter》2010,28(3):413-420
Cytometric and molecular techniques were used to verify genetic uniformity among somatic embryo-derived plantlets of Gentiana pannonica Scop. Cytometric analysis of regenerants revealed absence of chromosomal changes and alterations in ploidy. However, reverse
phase high pressure liquid chromatography detected higher levels of methylation in regenerated plants than those of control
plants. These changes were further investigated using a quantitative molecular marker-based approach. This revealed that numerous
tissue culture-induced variations, ∼3% (epi)mutations, were observed, including sequence variation and changes in methylation
patterns. Moreover, complex patterns of variation, including combinations of genetic and epigenetic changes, were relatively
high (ca. 9%). Overall, tissue culture-induced variation reached 16%; while, demethylation was lower than de novo methylation
in heterozygotic material and similar in all regenerated plantlets. 相似文献
57.
Agnieszka Kiełkowska 《Cytology and Genetics》2017,51(6):478-484
Salt stress severely affects plant growth and regulation; however knowledge about its effect on cytological changes is limited. In this report, studies were carried out to reveal the morphological and cytogenetic responses of the Allium cepa roots after prolonged (7, 14, 20 days) exposure to salt stress in tissue culture conditions. Roots of plants were treated with different concentrations (100, 200, 300 mM) of NaCl and KCl added to the culture medium. Both salts caused root growth reduction and showed cytotoxic effect reflected in reduction of root tip cells mitotic activity and increase of different abnormalities such as chromosome breaks and bridges and formation of micronuclei. This experiment showed differences of the action of excessive amounts of both tested salts at the cellular level, as KCl induced higher frequencies of abnormalities during cell divisions, whereas NaCl showed more mitodepressive effect and more frequently led to the root meristem cell death. 相似文献
58.
Agnieszka Wolnicka-Glubisz Frances P Noonan 《Photochemical & photobiological sciences》2006,5(2):254-260
UV irradiation has multiple effects on skin including erythema, immunosuppression and the induction of keratinocyte-derived skin cancers and cutaneous malignant melanoma (CMM). CMM which arises from damage to the melanocyte, the pigment cell of the skin, is associated in epidemiologic studies with sun-exposure of susceptible populations, especially children. Our experimental studies have supported the concept that the epidemiologically observed susceptibility in children has a biologic basis. Hepatocyte growth factor/scatter factor (HGF/SF) transgenic mice neonatally irradiated with UV produce melanomas which recapitulate human disease in histopathology and molecular pathogenesis. In this model, neonatal UV is necessary and sufficient for melanoma induction although an additional adult dose of UV radiation significantly increased melanoma multiplicity. One hypothesis for the susceptibility of neonatal mice to induction of melanoma is that neonatal skin contains a large number of immature melanocytes which may result in the retention of the consequences of UV damage throughout the lifetime of the animal. An alternate hypothesis is that the immaturity of the neonatal immune system results in tolerance to melanocytic antigens produced by UV exposure, thus permitting the subsequent outgrowth of melanoma. Here, we discuss the current state of knowledge about the differences between adult and neonatal mice in melanocytes and immune maturation as possible factors playing a role in the susceptibility to melanoma in UV irradiated HGF/SF transgenic mice. 相似文献
59.
Tadeusz Janas Agnieszka Janiak-Osajca Teresa Janas 《Journal of biological physics》1995,21(4):295-306
The application of the theory of homeomorphic transformations of topological manifolds and the operation of the connected sum of manifolds for a formation of a topological model of membrane transformations during the division process of cellular and subcellular compartments, has been shown. The biological cell and the subcellular structures in the form of vesicles are modelled by an arrangement of two concentric spheres corresponding to the inner and outer layer of the membrane bounding the vesicle. The analysis shows eight succeeding topological stages of membrane transformations during the division process and these stages are characterised. It is concluded that there is a vectorial translocation of lipid molecules from the inner layer of the membrane bounding the vesicle before the division process to the outer layer of the membranes after the division process and there is no lipid translocation from the outer layer to the inner layers during the division process. 相似文献
60.
New synthetic pathway towards 19-functionalized derivatives of 1alpha-hydroxy-5,6-trans-vitamin D3 was described. Ring-closing metathesis (RCM) of 1alpha-hydroxy-5,6-trans-vitamin D3 1-omega-alkenoates was a key-step. Hydride reduction of resulting lactones led to the new vitamin D3 analogues. 相似文献